Submission #766740

#	Time	Username	Problem	Language	Result	Execution time	Memory
766740		Dorost	Power Plant (JOI20_power)	C++17	0 / 100	3 ms	4948 KiB

power

/*  * In the name of GOD  */

#include "bits/stdc++.h"

using namespace std;

typedef long long ll; 
typedef pair <int, int> pii;
#define F first
#define S second
#define mk make_pair
const int N = 201234;
vector <int> g[N];
int dp[N][2];
bool f[N];

void dfs (int v, int p = -1) {
    if (f[v]) {
        dp[v][1] = 1;
    }   
    int sum1 = 0;
    for (int u : g[v]) {
        if (u != p) {
            dfs (u, v); 
            dp[v][0] = max(dp[u][0], dp[v][0]);
            if (f[v])
                dp[v][0] = max(dp[u][1] + 1, dp[v][0]);
            sum1 += dp[u][1];
        }
    }   
    if (f[v]) {
        dp[v][0] = max(dp[v][0], sum1 - 1); 
        dp[v][1] = max(dp[v][1], sum1 - 1); 
    } else {
        dp[v][1] = max(dp[v][1], sum1);
        dp[v][0] = max(dp[v][0], sum1);
    }   
}

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie();
    cout.tie();
    int n;
    cin >> n;
    for (int i = 0; i < n - 1; i++) {
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }   
    for (int i = 1; i <= n; i++) {
        char c;
        cin >> c;
        f[i] = (c - '0');
    }   
    dfs (1);
    cout << dp[1][0];
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 53